Systems and methods for eliciting cutaneous sensations by electromagnetic radiation

ABSTRACT

The present disclosure provides various systems and methods for inducing cutaneous sensations by delivering electromagnetic radiation to directly or indirectly excite neural tissue. An electromagnetic radiation source, such as one or more infrared lasers, may be used to transcutaneously excite neural tissue. The excited neural tissue may be interpreted by the user&#39;s nervous system as cutaneous sensations. Accordingly, a system as described herein may be used to induce sensations to allow actual cutaneous sensations to be simulated. A system for inducing a cutaneous sensation via transcutaneously focused electromagnetic radiation may be incorporated in a display to provide cutaneous sensation feedback or used as a separate accessory component associated with a display. Numerous additional applications and variations are provided herein.

RELATED APPLICATIONS

The present application claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application No. 61/579,776, filed Dec. 23, 2011,and titled “SYSTEMS AND METHODS FOR OPTICALLY EXCITING NEURAL TISSUE FORHAPTICS APPLICATIONS;” Provisional Patent Application No. 61/585,741,filed Jan. 12, 2012, and titled “SYSTEMS AND METHODS FOR OPTICALLYEXCITING NEURAL TISSUE FOR HAPTICS APPLICATIONS;” Utility Patentapplication Ser. No. 13/722,844, filed Dec. 20, 2012, and titled“SYSTEMS AND METHODS FOR ELICITING CUTANEOUS SENSATIONS BYELECTROMAGNETIC RADIATION;” Utility patent application Ser. No.14/037,290, filed Sep. 25, 2013, and titled “SYSTEMS AND METHODS FORELICITING CUTANEOUS SENSATIONS BY ELECTROMAGNETIC RADIATION, all ofwhich are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure is directed to systems and methods for directlyor indirectly exciting neural tissue using electromagnetic radiation.More particularly, the present disclosure is related to stimulation ofneural or other excitable tissues using electromagnetic radiation forinducing cutaneous sensations.

BRIEF SUMMARY

According to various embodiments, a system for inducing—cutaneoussensations, may comprise an electromagnetic radiation emission systemconfigured to emit electromagnetic radiation suitable for directly orindirectly exciting neural tissue. The system may also include anelectronic display configured to display a graphical user interface anda detection system configured to detect a point of contact (such as afinger contact) with the display. A controller configured to transmit acontrol signal to the electromagnetic radiation emission system to causethe electromagnetic radiation emission system to direct electromagneticradiation at the contact detected by the detection system to directly orindirectly excite neural tissue associated with the contact in order toinduce a cutaneous sensation. According to some embodiments, theelectromagnetic radiation emission system may further comprise at leastone focusing element controllable for selectively focusing theelectromagnetic radiation emitted by the electromagnetic radiationemission system. Transcutaneously focused electromagnetic radiation mayinclude single or multiple beams of electromagnetic radiation coincidentat a focal point. Alternatively, a splitting element may be utilized insome embodiments in order to direct electromagnetic radiation from onesource of electromagnetic radiation to a plurality of points of contact.Another embodiment would be a single source of electromagnetic radiationemission that is redirected or switched by the controller to individualfiber optic lines (e.g. an optical switch), which are spatially arrangedto allow for specific illumination/irradiation at specific points on theuser. Finally, some embodiments may incorporate multiple sources ofelectromagnetic radiation that may be selectively directed towardmultiple points of contact.

The system may further comprise a storage medium containing a library ofcutaneous sensations, each of which may be defined by a set ofcharacteristics of the electromagnetic radiation. The controller may beconfigured to modulate the characteristics of the electronic radiationemitted by the electromagnetic radiation emission system to induce aspecific cutaneous sensation. These individual or pre-defined sensationscan also be combined and tailored via the controller to create uniquecutaneous sensations.

At least one of the cutaneous sensations may be defined by a set ofcharacteristics of the electromagnetic radiation in at least twolocations in the neural tissue separated by more than a two-pointdiscrimination region. The controller may be configured to modify ormodulate one or more characteristics of the electromagnetic radiationemitted by the electromagnetic radiation emission system to induce acutaneous sensation corresponding to an object displayed on thegraphical user interface at the location of the contact with theelectronic display. According to some embodiments, the characteristicsof the electromagnetic radiation modified or modulated by the controllermay include pulse width, pulse repetition rate, shape, amplitude,fluence, depth, frequency, location(s), spot size, wave shape, dutycycle, rasterization patterns, and the like.

The electromagnetic radiation emission system may comprise Light-EmittedDiodes (LEDs) or various forms of laser sources, including edge-emittingand surface emitting semiconductor lasers for example, and nonlinearfrequency conversion of these laser sources. Of course, according tovarious embodiments, other types of visible and electromagneticradiation sources may also be utilized.

The electronic display may be a touch screen electronic display, and thedetection system may utilize a touch screen digitizer or the like of thetouch screen electronic display to detect the contact and determine thepoint of contact or area of contact with the user. The electromagneticradiation emission system may be part of a moveable stage configured tomove relative to the plane of the electronic display, and the controllermay be configured to control the movement of the stage to direct theelectromagnetic radiation to the contact detected by the detectionsystem. The stage may comprise at least one magnet, and the controllermay be configured to control the movement of the stage relative to theplane of the electronic display using a series of electromagnetsproximate at least two edges of the electronic display. Alternatively,other forms of mechanical actuation may be utilized to reposition themoveable stage. The moveable stage will allow for mounting one of amirror(s) and a focusing element(s) such as a lens that can direct theincoming electromagnetic radiation from the perimeter of the display toperpendicular to the plane of the display and into the point of usercontact.

Alternatively, the electromagnetic radiation emission system may beconfigured to direct the electromagnetic radiation to the point ofcontact detected by the detection system via the stage via fiber opticcable mounted to a moveable stage. The controller may be configured tocause the electromagnetic radiation emission system to transcutaneouslyfocus electromagnetic radiation at the contact using a processionpattern bounded by a two-point discrimination region.

The system may further comprise a sub-threshold electrical stimulationsystem configured to electrically stimulate a portion of the user.According to some embodiments, the electrical stimulation system is usedto elicit electrical stimulation to achieve a subthreshold value thatcan later use electromagnetic radiation to achieve the threshold andachieve sensation. The controller may be further configured to adjustthe fluence of the electromagnetic radiation based on calibrationresults. For example, the calibration results may define a minimumenergy density to induce a cutaneous sensation in the contact. Thecalibration results may be obtained from a calibration phase, performedby directing electromagnetic radiation of various fluences at the pointof contact, receiving feedback from a user indicating which of theelectromagnetic radiation pulses induced a cutaneous sensation in thecontact; and associating a minimum energy density to induce a cutaneoussensation with the lowest fluence indicated by the user as havinginduced a cutaneous sensation.

The system may further comprise a thermal feedback system configured tomeasure a temperature associated with the contact, and the controllermay be configured to dynamically control the electromagnetic radiationemission system to only deliver the appropriate fluence to achieve thedesired stimulation. According to one embodiment the temperature of thefinger or other body part is determined by a thermistor, or the like, toprovide the control system with an indication of the skin temperature.According to another embodiment, the temperature of the glass ismaintained at a certain known temperature using feedback from anembedded thermistor, or the like, to provide an indication of the glasstemperature.

The thermal feedback system may comprise a non-contact infraredthermometer, a thermistor, and/or a thermocouple.

The system for inducing cutaneous sensations may be implemented on auser interface component instead of or in addition to a display. Adiscrete user interface component may be associated with a display insome embodiments. The user interface component may comprise a track pador a keyboard or a mouse key or any portion thereof. According to someembodiments the user interface component may comprise an enclosure, andthe enclosure may be configured to receive at least one finger (or otherportion of the user, such as a hand) within the enclosure. The enclosuremay comprise a glove configured to enclose two or more fingers, a fingerwrap configured to receive a single finger, or a hand enclosureconfigured to receive a hand. According to one embodiment, a finger wrapor finger sleeve may include embedded fiber optic lines. An opticalswitch may be used to deliver electromagnetic radiation to a targetarea. Further, such embodiments may be configured to deliver arasterized pattern of electromagnetic energy in order to stimulatemultiple target areas.

The user interface component may be associated with a display, and thecontroller may be configured to modify one or more characteristics ofthe electromagnetic radiation emitted by the electromagnetic radiationemission system to induce a cutaneous sensation corresponding to anobject displayed on the display. The system may be integrated into aperipheral computing device configured to allow a user to provide inputto a computing device, and the user interface component may comprise asurface of the peripheral device. The peripheral computing device maycomprise one of a computer mouse and a computer keyboard, and the userinterface component comprises a surface of a button.

In one embodiment, a system for communicating visual information viacutaneous sensations may comprise an imaging device configured to imageat least one object; an electromagnetic radiation emission systemconfigured to emit electromagnetic radiation suitable for directly orindirectly exciting neural tissue. The system may further include aninterface component configured to deliver electromagnetic radiation to atarget area of a user's skin and a controller configured to controloperation of the electromagnetic radiation emission system. Thecontroller may map at least one object imaged by the imaging device to acutaneous sensation and transmit a control signal to the electromagneticradiation emission system to cause the electromagnetic radiationemission system to deliver electromagnetic radiation at the point ofcontact to directly or indirectly excite neural tissue and therebyinduce a cutaneous sensation at the point of contact.

In another embodiment, a multi-layer display configured to inducecutaneous sensations may comprise a touch screen digitizer layer or thelike configured to detect a point of contact with a user. Themulti-layer display may also include an electronic display layerconfigured to display objects; a spatial light modulator (SLM) layerconfigured to dynamically focus and steer electromagnetic radiation; aVCSEL and lenslet array layer configured to selectively emitelectromagnetic radiation suitable for exciting neural tissue. Acontroller may be configured to control the SLM layer and the VCSEL andlenslet array layer to deliver electromagnetic radiation at the point ofcontact to thereby directly or indirectly excite neural tissue to inducea cutaneous sensation at the point of contact.

A method for inducing cutaneous sensations may comprise displayinggraphical information on an electronic display; detecting a point ofcontact with a user on the display; and transcutaneously focusing andsteering electromagnetic radiation at the contact of the finger toexcite neural tissue in the finger to induce a cutaneous sensation.

Various methods are also disclosed herein for inducing cutaneoussensations. Such methods may include displaying a graphical userinterface on an electronic display and detecting a point of contact of afinger on a haptic feedback surface associated with the electronicdisplay. Further the method may include generating a control signal tocause an electromagnetic radiation emission system to deliverelectromagnetic radiation. In response to the control signal,electromagnetic radiation may be delivered at the point of contact todirectly or indirectly excite neural tissue in the finger and therebyinduce a cutaneous sensation.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the disclosure aredescribed herein, including various embodiments of the disclosureillustrated in the figures listed below.

FIG. 1 illustrates a block diagram of a system for exciting tissue usingelectromagnetic radiation, according to certain embodiments.

FIG. 2 illustrates a simplified embodiment of a system for deliveringelectromagnetic radiation onto a finger of a user, according to certainembodiments.

FIG. 3 illustrates a simplified embodiment of multiple electromagneticradiation beams transcutaneously coincident within a finger of a user,according to certain embodiments.

FIG. 4 illustrates a display associated with a system for inducingcutaneous sensations via transcutaneously focused electromagneticradiation, according to certain embodiments.

FIG. 5A illustrates a touch screen configured to induce cutaneoussensations in a user's finger by delivering electromagnetic radiation toa point of contact with the user, according to certain embodiments.

FIG. 5B illustrates an accessory component configured to inducecutaneous sensations in a user's finger while using a display bydelivering electromagnetic radiation to a point of contact between theaccessory and the user, according to certain embodiments.

FIG. 5C illustrates a conceptual representation of an electromagneticradiation delivery system including a single electromagnetic radiationsource that may be incorporated into a finger sleeve or other device,according to certain embodiments.

FIG. 5D illustrates a conceptual representation of an electromagneticradiation delivery system 580 including a plurality of electromagneticradiation sources that may be incorporated into a finger sleeve or otherdevice, according to certain embodiments.

FIG. 6A illustrates an embodiment of a moveable stage fortranscutaneously rastering electromagnetic radiation to excite tissue,according to certain embodiments.

FIG. 6B illustrates another embodiment of a moveable stage fortranscutaneously rastering electromagnetic radiation to excite tissue,according to certain embodiments.

FIGS. 7A-C illustrate examples of rasterization patterns for inducingcutaneous sensations using electromagnetic radiation, according tocertain embodiments.

FIG. 8 illustrates an electro-optical system for inducing cutaneoussensations, including an electrical stimulation system and a system fortranscutaneously focusing electromagnetic radiation, according tocertain embodiments.

FIG. 9 illustrates a schematic of an initial user calibration procedureof a device including an electromagnetic radiation stimulation systemfor inducing cutaneous sensations.

FIG. 10 illustrates a block diagram of a system for inducing cutaneoussensations using electromagnetic radiation including a thermal feedbacksystem, according to certain embodiments.

FIG. 11 illustrates a system integrated within a peripheral device of acomputer for inducing cutaneous sensations using electromagneticradiation, according to certain embodiments.

FIGS. 12A-C illustrate three embodiments for directing electromagneticradiation to a point of contact using electromagnetic radiation within asurface, according to certain embodiments.

FIG. 13 illustrates an example of a display incorporating a system forinducing cutaneous sensations using electromagnetic radiation, accordingto certain embodiments.

FIG. 14A illustrates a schematic of a relatively thin fluid layerconfigured to provide ocular protection from electromagnetic radiationthat may be used to induce haptic sensations, according to certainembodiments.

FIG. 14B illustrates a finger depressing the relatively thin fluidlayer, thereby allowing electromagnetic radiation to penetrate the fluidlayer and induce a cutaneous sensation in the finger of the user,according to certain embodiments.

FIG. 15A illustrates an embodiment of a display incorporating a systemfor inducing cutaneous sensations using electromagnetic radiation and anarray of lenslets and/or VCSELs, according to certain embodiments.

FIG. 15B illustrates an embodiment of a display, in which collimatedelectromagnetic radiation traverses a transmissive spatial lightmodulator layer.

FIG. 15C illustrates an embodiment of a display including a spatiallight modulating layer, which may impose a grating or dot pattern forscanning stimulation spots and rasterization schemas.

In the following description, numerous specific details are provided fora thorough understanding of the various embodiments disclosed herein.The systems and methods disclosed herein can be practiced without one ormore of the specific details, or with other methods, components,materials, etc. In addition, in some cases, well-known structures,materials, or operations may not be shown or described in detail inorder to avoid obscuring aspects of the disclosure. Furthermore, thedescribed features, structures, or characteristics may be combined inany suitable manner in one or more alternative embodiments.

DETAILED DESCRIPTION

According to various embodiments, electromagnetic radiation may be usedto induce apparent cutaneous sensations in a user. Accordingly, thevarious embodiments of the systems described herein are configured toinduce cutaneous sensations through the application of transcutaneouselectromagnetic radiation. In some embodiments, mechanical deformationof the skin is used to produce tactile sensation. Challenges associatedwith using mechanical devices for creating haptic sensations may includethe inertia of moving parts and the difficulty in miniaturization tocreate sufficiently high resolution. In other embodiments, directelectrical stimulation of tissue may be used. However, electricalstimulation often has poor spatial resolution due to current spreadingbetween electrodes.

Electromagnetic radiation, such as light emitted in the infrared orvisible spectrum, may be applied to a user's skin in order to stimulateneural tissue in the skin and thereby induce action potentials, eitherdirectly or indirectly, at the site of irradiation. Irradiation of theskin that induces, either directly or indirectly, action potentials inthe peripheral nervous system which are highly spatially selective, andmay thus achieve high resolution and may be utilized in connection withmany applications.

Lasers may be used in ablative and non-ablative applications. Ablativelaser systems may impart sufficient energy to the tissue so that someportion of the tissue architecture may be destroyed or otherwisetransformed. For example, ablative lasers may be used in surgery toreplace or supplement the use of scalpels and cautery instruments.Ablative lasers may also be used in aesthetic dermatology to encouragedermal remodeling. At somewhat lower energies, both ablative andnon-ablative, systems may be adapted for port wine stain removal usingphotocoagulation techniques that selectively destroy the excessiveaccumulation of blood vessels.

Non-ablative laser technologies may apply lower energies or fluencesthan ablative lasers. Non-ablative lasers may be used to promote woundhealing, relax sore muscles, and potentially alter cellular function invarious ways. Low-level light therapy (LLLT) devices have applicationsin medical and veterinary uses, as well as in the field of dentistry.According to various embodiments described herein, electromagneticradiation may be used at wavelengths at energies that do not causetissue damage. According to some embodiments, the energy densityutilized by some embodiments may be higher than that of traditional LLLTdevices.

Electromagnetic radiation suitable for exciting neural tissue, eitherdirectly or indirectly, may include specific wavelengths or a range ofwavelengths, according to various embodiments. The application ofelectromagnetic radiation to nervous tissue may elicit actionpotentials. The system may utilize a wide range of one or more differentwavelengths between approximately 400 nanometers (nm) and 8000 nm,including but not limited to 650, 808, 850, 860, 885, 915, 940, 980,1064, 1120, 1310,1450, 1470, 1490, 1495, 1540, 1550, 1850, 1862, 1870,2000, 2100, 2120, 3000, 4000, and 6000 nm. The present disclosurecontemplates several different embodiments of the device with differentelectromagnetic radiation sources. For example, one embodiment uses alaser as the electromagnetic radiation source. In another embodiment,the electromagnetic radiation source may utilize one or more LEDs. Inanother embodiment, a flash tube broad-spectrum light source may beutilized. Any of a wide variety of electromagnetic radiation sourcescapable of delivering electromagnetic radiation at a sufficient powerdensity may be utilized. Some embodiments may utilize a singlewavelength source, filter all but a single wavelength of abroad-spectrum source, and/or utilize a multi-wavelength source ofelectromagnetic radiation. In some embodiments, a filter may be placedat any point between the electromagnetic radiation source and the tissueto be stimulated.

The present disclosure provides various embodiments of systems andmethods for inducing cutaneous sensations using transcutaneouslydelivered electromagnetic radiation. As used herein, the termselectromagnetic radiation represents the breadth of the electromagneticspectrum, as applicable to the present disclosure. In variousembodiments, tissue may be transcutaneously irradiated for the purposeof simulating the sensations of cutaneous touch. The cutaneoussensations may represent physical traits of actual objects at a remotelocation, or can represent simulated objects.

For example, a system for inducing cutaneous sensations usingtranscutaneously delivered electromagnetic radiation may be used for anynumber of tactile applications, such as, but not limited to,telepresence medicine, compact electronic Braille displays, virtualproduct online shopping, representing virtual and physical objects anddrawings in computer generated images and computer aided drafting (CAD),for touch screen feedback, control feedback, and/or entertainment andgaming devices. The use of electromagnetic radiation for stimulatingneural tissue may be more responsive than a mechanical system and mayprovide higher spatial resolution than a purely electrical system. Inaddition, the lack of moving parts may result in higher reliability andlower maintenance of the system.

In some embodiments, transcutaneously delivered electromagneticradiation may be used to induce cutaneous or subcutaneous sensations foruse in less-than-lethal weapons. Less-than-lethal weaponry is widelyused by military and police forces for crowd control and othersituations where slowing or immobilizing a person is preferable tocausing serious injury or death. Transcutaneous application ofelectromagnetic radiation may be used to cause a sensation on or beneaththe skin. For example, a less-than-lethal weapon utilizingtranscutaneously applied electromagnetic radiation may be used to causesensations associated with burning, pressure, scraping, cutting, and/orother unpleasant or painful sensations that may deter a person from aparticular course of conduct. Such a system may be configured to causeno damage, or minimal damage, to tissue. Rather, the system may simplyinduce sensations in the brain as being extremely unpleasant orinjurious.

In some embodiments, a patch or plate, which is adhered to the skin, maybe used to transmit electromagnetic radiation to/through the skin. Sucha device may be adapted to communicate tactile information to the wearerdiscretely and/or silently. Such a system may be used in silent militaryapplications.

In some embodiments, a system configured to induce cutaneous sensationsvia transcutaneously focused electromagnetic radiation may be used toinduce pleasant sensations as well. For example, a system may be adaptedto comfort and/or calm premature infants in incubators. The system maysimulate human contact without exposing them to the contamination thatthe incubator intends to avoid. In some embodiments such a patch couldprovide comfort to older patients as well. Those afflicted withdepression, seasonal affective disorder, or other mental illness thathave shown response to vagal nerve stimulation. Cutaneous stimulation onthe proper body parts may also help alleviate some of their symptoms.Also, in autism and other developmental disorders many individualsengage in autostimulation behaviors. In some of these cases theautostimulation behavior can cause serious injury. Optical stimulationof these patients may prove to satisfy the desire for stimulation in aless injurious manner.

A system may utilize a control program to control the application ofelectromagnetic radiation. For example, the electromagnetic radiationmay be directed to the tissue in such a way that only a small portion ofthe tissue is irradiated. The tissue may be excited in such a way thatthe brain perceives it as mechanical stimulation. The amount of energyimparted to the tissue may be the minimum necessary to reliably andreproducibly elicit the desired response. In some embodiments, thecontrol program may be calibrated for a set of users and/or a specificuser. In some embodiments, a feedback mechanism may be used todynamically adjust the output. For example, the control program may beinitially calibrated and then dynamically adjust the amplitude, focus,rasterization pattern, and/or other attributes of the electromagneticradiation based on a thermal sensor to protect the skin from damage.

The control program may utilize an infrared imaging device or othertemperature probe to detect the surface temperature of the skin and makeappropriate adjustment to the stimulation protocol. In anotherembodiment the feedback may be quasi-closed loop and may be accomplishedby incorporating calculations from a proprietary computer simulation,and/or empirical data collected from various human or phantom tissuetesting in the form of a look-up table where the stimuli delivered areknown to change the tissue temperatures and subsequent stimuli areadjusted accordingly.

Tactile and/or other cutaneous sensations may be created by theactivation of mechanoreceptors that are normally triggered. Thesereceptors are distributed unequally in different areas of the skin. Inorder to selectively stimulate a different number of receptors, neuronalaxons, or other excitable tissues the application of optical energy maybe applied in a controlled manner.

In some embodiments, a plurality of optical focusing devices may be usedto direct electromagnetic radiation to the tissue. This may beaccomplished through the use of any combination of lenses, mirrors,fiber optics, and/or other electromagnetic manipulation materials. Theincident electromagnetic radiation may be focused to provide a spotsize, large enough to assure stimulation of excitable tissues, whileremaining small enough that collateral heating of non-excitable tissuesare minimized. The beam shape of the electromagnetic radiation may becontrolled to limit collateral heating of non-excitable tissues. Forexample, a highly converging beam with short focal region may be focusedat or beneath the skin surface. In other embodiments, theelectromagnetic radiation may comprise several beams of electromagneticradiation focused transcutaneously. Focusing electromagnetic radiationmay include the utilization of optical components such as lenses and/ormirrors, and/or the usage of coincident beams of electromagneticradiation. The focal point(s) may be at a location(s) within the tissuewhere electromagnetic radiation can be used to produce neuralexcitation.

In some embodiments, to avoid overheating of a single area of tissue,beam procession may be used within a small area. The procession of thebeam may be confined to an area where different stimuli are spatiallyindistinguishable by the brain. In other words, the area of confinementfor the procession may be experienced by the user as stimulation of thesame point on the skin. Accordingly, two-point discrimination may varydepending upon which area of a user's body is irradiated.

Accordingly, by rasterizing the applied beam of electromagneticradiation, the system may stimulate many points on the skinsimultaneously, or nearly simultaneously, and/or may reduce cutaneousand/or subcutaneous thermal buildup. In one embodiment, the beam isscanned or rastered through the use of a device, such as agalvanometer-based optical scanner. In another embodiment, one or moreprisms may split the beam and the split beams may be shuttered, such asvia a mechanical and/or liquid crystal display (LCD) based spatial lightmodulation system. In another embodiment, a Spatial Light Modulator(SLM) may be used to dynamically modify the wave front of theelectromagnetic radiation in order to adaptively focus the beam insidethe skin layer. A grating structure can also be written on the same SLMin order to scan the electromagnetic radiation over the skin.

In another embodiment, the beam may be split and transmitted via amulti-bundle fiber array combined with shutter control at the output ofeach of the fibers from the bundle. In one embodiment, optical rasteringcan be implemented by the use of a fiber bundle with N fibers and a 1×Noptical switch. The stimulation light can come from either a singleLED/laser source, or it can be the combined output from M LED/lasersources. By connecting a 1×N optical switch to an N-fiber bundle, thelight can be sequentially directed to any one of the N-fibers in thebundle by the use of the optical switch.

In another embodiment, digital light processing technology may be usedto split and direct multiple beams. In one embodiment, a two-dimensionalmotion stage, described in terms of an X-Y coordinate system, may beused to move the electromagnetic radiation source. In some embodiments,a tilting mechanism may be used to adjust the incident angle and allowfor a greater area for beam delivery. That is, the electromagneticradiation source may be moved within a limited two-dimensional arraycombined with a tilting mechanism to widen the effective two-dimensionalrange of the system.

Any of the variously described embodiments of systems for inducingcutaneous sensations via transcutaneously focused electromagneticradiation may be integrated within a display, such as a touch screendisplay. For example, a system may be integrated within an LCD ororganic LED (OLED) screen. For example, a system may be integrated andassociated with a pixel or cluster of pixels adjacent to anelectromagnetic radiation source or electromagnetic radiationtransmission element. The system may be configured to provide tactilefeedback associated with the display or touchscreen display. In otherembodiments, the electromagnetic radiation source and/or electromagneticradiation transmission element(s) may be placed behind a display that istransparent to the electromagnetic radiation so that the electromagneticradiation passes through the display or vias built into the display.

For example, the electromagnetic radiation may be directed through thesurface of a touch screen display into the finger, fingers, and/or handof a user to induce a cutaneous sensation. A system, according to any ofthe embodiments described herein, may be integrated into an interactivedisplay such as on a smartphone, tablet computer, computer monitor, ortelevision. In such devices, the location or placement of a finger orother object may be determined by hardware built directly into thescreen and/or software. The location and contact area information may beutilized by the system to irradiate only when and where tissue (e.g., afinger) is present. In addition to location and contact areainformation, movement attributes such as speed and direction may bedetermined and used by the control system to dynamically adjust theelectromagnetic radiation transmission settings. For example, thesensations induced by the transcutaneously focused electromagneticradiation may simulate a textured surface. The textured surface felt maybe dynamic and/or changeable. The sensations could also be used asfeedback for actions performed, such as a button press. The stimulationsurface may also be a track pad or other dedicated non-display surfacethrough which the electromagnetic stimulating energy may pass.

In one embodiment, a system for inducing cutaneous sensations usingtranscutaneously focused electromagnetic radiation may be embodied as anoff-display device associated with a second device. For example, asystem may interact with a user's single finger, multiple fingers, or afull hand. In some embodiments, users may insert a portion of theirbodies, such as a finger, hand, arm, etc. within the stimulating area ofthe device. The user, or portion of the user inserted within the system,could be held immobile or allowed to move. The system may inducesensations associated with virtual objects such that they feel orprovide simulated sensations associated with corresponding physicalobjects. In some embodiments, the portion of the user to be irradiatedwith electromagnetic radiation may be decoupled from other surfaces, soas to limit sensations other than those induced via the transcutaneouslyfocused electromagnetic radiation.

In some embodiments, the off-display embodiment may be passive in thesense that the tissue to be stimulated cannot move to interact with adisplay of the object being represented. In other embodiments, theoff-display embodiment may be partially interactive by allowing thefinger(s) and/or hand to move and/or respond within the off-displaysystem. In such an embodiment, the system may track movement and makeappropriate adjustments to the stimulating beams for appropriate focus.

In another embodiment, a covering or housing may be secured to afinger(s) or hand of a user that allows the user to interact with adisplay. The covering may prevent the finger(s) or hand from receivingmechanical stimulation, such as from the surface of the touch screendisplay. Electromagnetic radiation may be directed onto the fingerpad(s) of the user via fiber optics and/or other lenses or mirrorswithin the covering. The fiber optics may be connected to a remoteelectromagnetic radiation source. The covering may allow for interactionwith a display or other interface. The electromagnetic radiation mayinduce sensations during the interaction and the covering may limitextraneous sensations (such as the texture of the display). In someembodiments, the display may be a computer or phone screen. The displaycould also be a holographic or virtual reality display presented in twoor three-dimensions.

A library of stimulation protocols may dictate the various sensationsthat can be induced by the system. Appropriately stimulating differentreceptors, axons, dendrites or other excitable tissues withelectromagnetic radiation at the appropriate place on/within the skinand with the appropriate repetition rates may be used to effectivelyreplicate tactile stimulation sensations experienced by touching aphysical object. A library may contain the basic components of complexsensations that, when combined appropriately, are capable of inducing awide range, or even all, of the cutaneous sensations, including, but notlimited to, those involving textures, pain, hot, cold, wet, dry, sticky,etc. Thus, a controller may modify the characteristics of theelectromagnetic radiation to change the pulse width, shape, amplitude,energy density, duty cycle, frequency, depth, location(s), spot size,wave shape, modulation characteristics, rasterization patterns and/orother characteristics of the electromagnetic radiation beam to induceany of a wide variety of cutaneous sensations. In some embodiments,these pre-defined cutaneous sensation effects can be combined and mixedappropriately to create new sensations within predetermined safetylimits to prevent harm to the user.

The stimulation protocols may include waveforms of various shapes andpatterns. The various pulses delivered are combined into trainsconsisting of, but not limited to, square, triangular, trapezoidal, andsinusoidal shaped pulses. Electromagnetic radiation may be continuouslyemitted, pulsed, electronically shuttered, pulse-width modulated (PWM),and/or otherwise modulated or pulsed. The spot size of the incidentelectromagnetic radiation may also be varied to create different sensoryeffects. This spot could be dynamically altered by movable lenses and/orby a variable aperture.

Obtaining tactile information may be done by a number of differentmeans. In one embodiment, a system may be configured to obtain tactileinformation for replication using an ultrasonic probe. An ultrasonicprobe may be used to gather topographical information of an object, howcompliant an object is, and/or subsurface characteristics of an object.In some embodiments, a laser may be used to determine thecharacteristics of a surface of an object. In some embodiments, a 3-Dcamera system may also be used to capture surface characteristics of anobject. In another embodiment, a series of probes mounted on calibratedsprings may be utilized to mechanically determine characteristics of asurface. As the spring is compressed, its displacement gives theappropriate information about the object's properties. Additionally, adifferential transformer may be used to measure linear or translationaldisplacements on a surface.

In one embodiment, a system, as described herein, may be utilized by theuser to measure physical characteristics of objects and inducecorresponding sensations for the user. For example, an imaging devicemay be used to scan the surface of an object. The system may translatethe image into a series of tactile sensations to be induced usingtranscutaneously focused electromagnetic radiation. In some embodiments,characteristics such as color, grey scale, line thickness, temperature,and the like, may be translated into tactile sensations.

In one embodiment, a sub-threshold electrical stimulation system may becombined with transcutaneously focused electromagnetic radiation. Forexample, electrodes may be placed near or at the location of the userwhere electromagnetic radiation is to be received. The electrodes may beconfigured to provide sub-threshold stimuli in the general area.Accordingly, the electrodes themselves may not produce any actionpotential in the mechanoreceptors or their afferent axons. Theelectrical stimuli may be cyclic at high rates corresponding to thenecessary electromagnetic stimulation. Electromagnetic radiation may beapplied in conjunction with the cyclical electrical stimuli. Accordingto such an embodiment, since the electrical stimuli provides asub-threshold stimulation, the electromagnetic radiation may be used toinduce cutaneous sensations at lower energy densities and may alsoprovide for greater selectivity of action potentials from Aβ and Aδneural fibers that convey tactile information over C fibers that carrypain and thermal information.

In one embodiment, the tactile information conveyed by a system asdescribed herein may be associated with a tactile logo or tactilesignature. A static or dynamic sensation may be incorporated into anynumber of applications. For example, a tactile logo may be felt beneatha visually displayed web page. The logo may not be visually displayedand only felt by the user. Such functionality could be incorporated inboth on-display and off-display systems as described herein.

For example, the tactile logo could be generated constantly beneath thefinger every time the finger is in contact with the screen.Alternatively, the tactile logo may be associated with specificdisplayed content, such as, but not limited to, a text, images, and/oranimation delivered to the user, such that when a specific object ortext is touched by the user, the logo is felt. A recognizable tactilelogo could let the user know who is sponsoring a certain web page, thata page is secure, or in another application without taking up visualspace on the screen. This may be particularly valuable on a mobile phoneor other device with limited screen space. Customers could purchasetactile logos for inclusion on personal or company web pages,applications, and/or the like.

Tactical representations may be encoded similar to black and whitedigital photographs. For example, a tactical representation may berepresented by x and y coordinates with amplitude or depth informationencoded at each point. Each point may be called a tixel (tactile imageelement). The number of tixels and the range of possible representations(e.g., bits) for amplitude or depth information may define theresolution of a tactile representation. Each surface of an object may berepresented by a tactile image or code. With a library of such imagesthe surfaces of these objects may be represented as a correspondinginduced sensation to the user. In another embodiment, thermal imagesthat show temperature fields or gradients can be represented as tixelsand representations (e.g., bits) for temperature or temperaturegradients may define the resolution of a tactile thermal representation.

In many embodiments, the user interface may be a flat surface on top ofwhich cutaneous sensations are created. In such embodiments, the surfacetextural information and an object's shape and compliance may beconveyed to the user. In another embodiment, an object's temperature andtemperature gradient information may be conveyed to the user. Inembodiments in which a user's hand, finger, or other portions of thebody are free to move in three dimensions, the surface information of athree-dimensional object may be conveyed.

A library of cutaneous tactile sensations and effects may be collectedand stored in a control program or a separate memory location.Additionally, custom or combinations of sensations may be created.Sensations can be derived from a combination of pre-formed sensationsdynamically calculated in software or stored for subsequent retrievaland use. Sensations may be based on empirical data, based onphysiological testing, algorithmic data, and/or derived from initialcalibration data. In one embodiment, algorithms used to determinesensations may account for variables, including but not limited toreflectance, temperature, finger speed, finger pressure, and tixel datato appropriately deliver the desired sensation(s).

In various embodiments, a controller or control system may beimplemented as any combination of hardware, firmware, and/or software.For example, a controller may be implemented as a field-programmablegate array (FPGA). In some embodiments, an electronic controller may bedistinct from other components of the system for inducing sensationsusing transcutaneously focused electromagnetic radiation. The system mayinclude microprocessors and other electronic components associated withdisplays, touch screens, data storage, data connectivity, memory,non-transitory computer readable media, etc.

Some of the infrastructure that can be used with embodiments disclosedherein is already available, such as general-purpose computers, computerprogramming tools and techniques, digital storage media, andcommunication networks. A computing device or other electroniccontroller may include a processor, such as a microprocessor, amicrocontroller, logic circuitry, and/or the like. The processor mayinclude a special-purpose processing device such as application-specificintegrated circuits (ASIC), programmable array logic (PAL), programmablelogic array (PLA), a programmable logic device (PLD), FPGA, or anothercustomizable and/or programmable device. The computing device may alsoinclude a machine-readable storage device, such as non-volatile memory,static RAM, dynamic RAM, ROM, CD-ROM, disk, tape, magnetic storage,optical storage, flash memory, or another machine-readable storagemedium. Various aspects of certain embodiments may be implemented usinghardware, software, firmware, or a combination thereof.

The embodiments of the disclosure may be understood with reference tothe drawings, wherein like parts are designated by like numeralsthroughout. The components of the disclosed embodiments, as generallydescribed and illustrated, could be arranged and designed in a widevariety of different configurations. Furthermore, the features,structures, and operations associated with one embodiment may beapplicable to or combined with the features, structures, or operationsdescribed in conjunction with another embodiment. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of this disclosure.

Thus, the following detailed description of the embodiments of thesystems and methods of the disclosure is not intended to limit the scopeof the disclosure, as claimed, but is merely representative of possibleembodiments.

FIG. 1 illustrates a block diagram of a system 100 for exciting tissueusing electromagnetic radiation from a light source 130, according toone embodiment.

According to various embodiments, a system 100 may include a controlprogram, 110, a power source 120, a light source 130, one or moreoptical components 140 for transcutaneously focusing electromagneticradiation from the light source 130 on excitable tissue 150, and afeedback system 160.

As illustrated, the light source 130, or other electromagnetic radiationsource, may generate pulses of light at appropriate energies andduration to stimulate excitable tissues, mechanoreceptors, and/orinnervating afferent axons. According to various embodiments, the pulseduration of the light source 130 may be in the range from 1 μs to 500 msand stimulation frequency may be in the range from 0 Hz to 1000 Hz.Other pulse ranges and/or frequency ranges capable of stimulatingexcitable tissues may be utilized. In some embodiments, one or moreoptical components 140 may be used to focus the light on or within theexcitable tissue 150. The optical components 140, in conjunction withthe light source 130, may be configured to minimize radiation exposureof non-excitable tissue and/or avoid excessive heating of the excitabletissue 150. Light emitted by the light source 130 may, directly orindirectly, excite action potentials to induce sensations correspondingto tactile sensations, as interpreted by the central nervous system.

The feedback system 160 may measure skin temperature, pressure from theuser on the system, user movement relative to the system, and/or todetermine effectiveness of various incident energies and points ofstimulation. The feedback system may provide information to the controlprogram for dynamically adjusting the inducement of cutaneous sensationsvia the transcutaneously focused electromagnetic radiation emitted bythe light source 130. The control program 110 may be implemented inhardware, firmware, and/or software. The control program may communicatewith and/or control the feedback system 160, the optical components 140,the light source 130, and/or the power source 120.

FIG. 2 illustrates a simplified embodiment of a system 200 fordelivering electromagnetic radiation 220 focused 245 on a finger 210 ofa user. As illustrated, a wide beam of electromagnetic radiation 220 isfocused by a lens 230 such that the focused electromagnetic radiationconverges at or below the epidermal surface of the user's finger 210.Only at the focus point 240, is the radiation fluence sufficiently highto stimulate, directly or indirectly, an action potential within thefinger 210. The electromagnetic radiation may diverge 255 and/or beabsorbed/scattered after stimulating the action potential within thefinger 210.

According to various embodiments, units of energy may be expressed interms of fluence or Joules per square centimeter. In variousembodiments, the electromagnetic radiation 220 used to excite the actionpotential may be between 1 mJ/cm² and 100 J/cm². For example, the energyof individual pulses may be between approximately 0.1 and 25 J/cm².Outside of the focus point 240, the fluence may be sub-threshold foraction potential initiation and of lower fluence, resulting in lesstissue heating. In some embodiments, an actuator may mechanicallyrotate, move, vibrate, and/or otherwise direct the electromagneticradiation 220. In another embodiment, the electromagnetic radiation 220and/or the lens 230 may rotate, move and/or vibrate using beam steeringcapabilities due to mirrors, spatial light modulators, or other opticaland/or electrical methods. The actuator may control the procession ofthe electromagnetic beam to mitigate collateral tissue heating.

FIG. 3 illustrates a simplified embodiment of a system 300 fordelivering multiple electromagnetic radiation beams 320 and 330transcutaneously coincident, at 340, on a finger of a user. Two beams320 and 330 are shown in the illustrated embodiment, but any number ofbeams may be used. Each of the beams 320 and 330 may have insufficientenergy densities to excite tissue and, thus minimize the energy impartedto non-excitable tissue. The point of coincidence 340 may include thecombined energy densities of each of the beams 320 and 330 ofelectromagnetic radiation. Thus, at the point of coincidence 340, theenergy density may be sufficient to initiate an action potential. Insome embodiments, the size of the focus may be adapted to createdifferent sensory effects. In some embodiments, the size of the focalspot may also be dynamically adjusted.

FIG. 4 illustrates a display 430 associated with a system 420 forinducing haptic sensations via transcutaneously focused electromagneticradiation. In various embodiments, the system 420 may be incommunication with the display 430. Accordingly, a portion 415 of theuser 410 within the system 420 may receive cutaneous sensations inducedby transcutaneously focused electromagnetic radiation. As illustrated,the system 420 may be a hand enclosure configured to receive a hand of auser. In such an embodiment, a user may receive cutaneous sensationassociated with images, objects, icons, or the like on the display 430.In some embodiments, the finger or hand of the user may be immobilized.In other embodiments, the finger or hand of the user may move within thesystem 420 and/or be able to provide responses to the received cutaneoussensations induced by the system 420. The power supply, light source,lensing system, and feedback systems may be all housed in the singleenclosure. According to other embodiments, various components may behoused in multiple enclosures. Further, a user's finger or hand could besuspended at a distance above a stimulating surface rather than cominginto direct contact with a stimulating surface.

FIG. 5A illustrates a display screen 520 configured with a system toinduce cutaneous sensations in a user's finger 515 usingtranscutaneously delivered electromagnetic radiation. The illustratedembodiment is an example of an on-display configuration. Display 520could be part of a mobile device, such as a smartphone or tabletcomputer, a stationary device such as a desktop computer, interactivepublic display, industrial control station, surgical control station,and/or other interactive display device. In the illustrated embodiment,the finger 515 of a user 510 comes into contact with the display 520,upon which the image is displayed. In some embodiments, the opticalenergy may be delivered through the front of the display.

In one embodiment, a system for inducing cutaneous sensations viatranscutaneously focused electromagnetic radiation may be in the form ofa flat surface adjacent to or opposite a display surface. For example,on a mobile phone or a tablet computer, the system could be integratedinto a flat surface that is beside, beneath, and/or on the sides of adisplay surface. Such an embodiment may allow for tactile interactionwith the content displayed without obscuring any portion of the visualdisplay. A light source according to any of the various embodimentsdescribed herein may utilize various types of lasers, VCSELs, LEDs,and/or other high-density focusable light sources.

FIG. 5B illustrates an accessory component 560 configured to inducecutaneous sensations in a user's finger 515 via transcutaneously focusedelectromagnetic radiation while using a display 525. In the illustratedembodiment, the electromagnetic radiation may be transmitted through theaccessory device 560 (illustrated as a finger sleeve) into the finger515 of the user 510. The electromagnetic radiation may originate from aremote source and be transmitted via a fiber optic cable 565 to theaccessory component 560. In some embodiments, the accessory component560 may secure the finger 515 suspended away from the walls thereof toavoid mechanical stimulation due to physical contact with externalobjects, such as the display 525.

Optical components for focusing the electromagnetic radiation and/orfeedback sensors and components may be incorporated into the accessorycomponent 560. In some embodiments, an interaction mechanism between theexternal wall of the accessory component 560 and the display 525 mayallow the user to interact with the virtual or distant object shown onthe display 525 and experience the tactile sensations in a naturalmanner. For example, the interaction mechanism may utilize a laserdistance finder, capacitive touch screen, an image sensor, a camera, a3D or depth camera, and/or an ultrasound echolocation system.

FIG. 5C illustrates a conceptual representation of an electromagneticradiation delivery system 500 including a single electromagneticradiation source 574 that may be incorporated into a finger sleeve orother device, according to certain embodiments. System 500 may include aswitch controller 572 coupled to an optical switch 570. Electromagneticradiation source 574 may be coupled to optical switch 570. A pluralityof fiber optic cables 582 may be bundled in a cable 580.

An enlarged view of a distal end 578 of cable 580 shows the plurality offiber optic cables 582. Optical switch 570 may selectively directelectromagnetic radiation generated from electromagnetic radiationsource 574 to any one of the plurality of fiber optic cables 582.

FIG. 5D illustrates a conceptual representation of an electromagneticradiation delivery system 590 including a plurality of electromagneticradiation sources 574 a-574 d that may be incorporated into a fingersleeve or other device, according to certain embodiments. System 590 mayinclude a number of components that are similar to system 500, andaccordingly, similar reference numbers are utilized. System 590 alsoincludes a fiber combiner 576. System 590 may utilize a plurality ofelectromagnetic radiation sources 574 a-574 d in order to realize anincrease in power output, a decrease in the cost of the system or otherpotential advantages.

FIG. 6A illustrates an embodiment of a stage 615 with a moveableelectromagnetic radiation source 617 for rastering electromagneticradiation to transcutaneously excite tissue. A system, according to anyof the various embodiments described herein, may utilize a moveableelectromagnetic radiation source 617 to control where theelectromagnetic radiation is transcutaneously focused. In someembodiments the stage 615 contains the electromagnetic radiation source617 and optics, while in others it includes only the optics or only theelectromagnetic radiation source 617. In some embodiments, the stage 615may be behind a display 610 (or other user interface component such as atrack pad or dedicated haptic feedback surface), while in otherembodiments the stage 615 may be in front of the display 610. In thelatter embodiment, the stage 615 may be substantially transparent tovisible light, such that the display 610 is not or minimally impeded.The mechanism for moving the stage 615 may be mechanically and/orelectromagnetically controlled.

For example, as illustrated in FIG. 6B, the stage 650 may containlightweight permanent magnets 652 that would be attracted to or repelledfrom certain areas by a grid or array of controllable electromagnets655. These electromagnets 655 can reside either on the rear of thedisplay 640 or along a frame around the display 640, so as to notocclude the display 640 for the user. In an embodiment where theelectromagnetic radiation source is not incorporated into the stage 650itself, the source 660 may be in the same plane as the stage, but off tothe side of the field. The electromagnetic radiation may be directedfrom the source to the stage 650 where it is reflected and/or refractedby optical components and focused into the intended tissue.

The ability to raster the electromagnetic radiation beam may be usefulfor stimulating multiple points when simulating mechanical stimuli. Anyof a wide variety of rasterizing systems, methods, and patterns may beused. For example, a galvanometer based scanner or beam splitter withshuttering technologies may be utilized. Microelectromechanical system(MEMS) based reflection and direction of the beam may be used torasterize the beam. In one embodiment, the tip of one or more laserfibers with external optical lens(es) (i.e., separate from the deliveryfibers) may be attached to the stage 650. The laser fiber and externaloptics may be collectively called the laser head. The plan of theassembly and stage 650 may be parallel to the plane on which a finger,fingers, hand, or other portion of the body is to be stimulated. Thestage 650 may be moveable in order to reach all areas of the finger orfull hand.

A controller may move the stage 650 based position information in thex-y direction. The position of the stage 650 may be determined byencoders or position sensors 665 on each axis of the stage 650 and/ornear the edges of the display 640. The controller may also periodicallymove the beam, such that the procession irradiates a certain location onthe finger pad/hand for only a certain amount of time. The procession ofthe beam can be in multiple patterns, all contained within the areasmaller than two-point discrimination, as described above. FIGS. 7A-7Cillustrate three example procession patterns that may be used within atwo-point discrimination region to reduce thermal buildup on the tissue.FIGS. 7A-7C may also be examples of rasterization patterns used toinduce various cutaneous sensations at desired locations. In suchembodiments, the various points in the patterns illustrated in FIGS.7A-7C may be separated by more than two-point discrimination.

In some embodiments, the same tissue location may be irradiatedrepeatedly using different light source parameters, such as, but notlimited to, pulse widths, frequencies, energies and/or waveforms foreach pulse or series of pulses. The control system may track theenergies and exposure time delivered to each spot on the tissue andadjust the pulses based on the feedback data to induce the appropriatesensations and avoid injury. If the tissue is moved relative to thelight source, there may be a need to increase the power delivered to thepreviously unexposed tissues. Tracking tissue placement relative to thearea of irradiation may allow the control program to deliver theappropriate power to the tissue to induce the desired sensation.

FIG. 8 illustrates an electro-optical system 800 for inducing cutaneoussensations, including an electrical sub-threshold-inducing device 820and a system for transcutaneously focusing electromagnetic radiationaccording to any of the various embodiments described herein (notshown). As illustrated, electrodes 830 and 835 leading from anelectrical stimulator 820 may be attached to a finger 815 of user 810.The electrodes 830 and 835 may be attached away from the area to beoptically stimulated to avoid mechanical stimulation. The sub-thresholdelectrical stimulation may utilize any of a wide variety of waveformshapes, such as square 825, or another waveform, such as sinusoidal,triangular, trapezoidal, monopolar, and/or bipolar. The electricalstimulation may be sub-threshold for all or most sensory modalities. Itmay be used to reduce the activation threshold necessary to inducecutaneous sensations using transcutaneously focused electromagneticradiation. If the transmembrane potential of the mechanoreceptor, itsafferent axon, or other excitable cells are raised closer to the actionpotential threshold, then less electromagnetic radiation may be requiredto directly or indirectly initiate the action potential.

FIG. 9 illustrates a schematic 900 of a user calibration procedure,according to one embodiment. The energies required to transcutaneouslyinduce a cutaneous sensation using electromagnetic radiation may differfor each user. For example, the pigmentation and other intrinsiccharacteristics, such as the finger print pattern or skin opticalproperties, of each user's skin can be different. Accordingly, in someembodiments a controller may perform an initial calibration for eachuser and/or use.

A calibration procedure may include imparting energies that shouldinitially be sub-threshold, followed by successively higher energylevels. The user may respond by indicating to the control programwhether or not a sensation was felt. FIG. 9 illustrates progressivelyhigher energy levels as peaks 910, 920, 930, and 940, followed bytroughs 915, 925, 935, and 945, respectively. In some embodiments, thecontrol program may deliver the next, higher energy stimuli only afterreceiving some response or after a time period has passed during which aresponse would have been expected. A calibration procedure may also beused to determine the range of fluences that may be used (e.g., thelowest energy that can be felt and the highest energy density that won'tcause harm or be uncomfortable). The calibration procedure may be usedfor various cutaneous sensations, such as tactile andtemperature/heating sensations.

According to some embodiments, a calibration procedure may be based oncontinuously delivering groups of pulses that step up to higher energylevels after predetermined periods of time. Each group of pulses mayinclude a priming pulse that precedes a train of identical pulses. Thepriming pulse may reduce sensation latency at the new energy level.

Part of the calibration procedure may account for feedback variables,such as skin temperature, skin tone, incident pressure on stimulationsurface, finger speed, and duration of previous exposure. In someinstances, when using multiple fingers it is possible that differentfingers would have different calibration results. In such cases, theprogram or controller may keep track of the fingers individually,delivering the appropriate energies to each finger (or other region ofthe body).

FIG. 10 illustrates a block diagram of a system 1000 for inducingcutaneous sensations via transcutaneously focused electromagneticradiation, including a thermal feedback system 1050. As illustrated, anelectromagnetic radiation source and/or optics 1040 may impart energyvia a beam 1020 to tissue 1015. The energy may be the stimulus fordirect or indirect excitation of mechanoreceptors and/or neural or otherexcitable tissue. Output from the electromagnetic radiation source maybe adjusted based on tissue temperature to deliver the appropriateenergy to create sensation. At certain wavelengths the byproduct of thelight beam incident on the tissues may be thermal energy buildup (heat).A thermal feedback system 1050 may measure the radiation from thetissues to determine the temperature of the tissues. If the tissuesbecome too hot, then the controller 1030 may lower the intensity of thelight beam output by the system.

Any type of temperature sensor or detector, such as a thermistor, may beused to determine the temperature of the finger. The feedback system1050 may be in physical contact with the tissue 1015. In anotherembodiment, the thermal feedback system 1050 may be a non-contactsensor. A sensor may be placed to the periphery of the surface so as tonot distort or impede the passage of the stimulating light. Sensors maybe integrated into the surface or display and/or made from materialstransparent to the necessary wavelengths of stimulating light and, inthe case of a visible display, visible light. As with the thermal imagerabove, the temperature data may feed the algorithm(s) that adjust thestimulation output appropriately.

The temperature of the stimulating surface may be controlled. Forexample, in an embodiment where the tissue is in contact with a surfacethrough which stimulation passes. Such an embodiment may not have atemperature feedback system. The surface temperature could be activelyheated (or cooled) through any number of mechanisms including, but notlimited to, embedded electric heating filaments, thermoelectric heatpump, IR radiation, or directing the heat from other processes such asthe computer or graphics processor.

FIG. 11 illustrates a system 1100 for transcutaneously inducingcutaneous sensations integrated within a peripheral device 1153 of acomputer. A sensation-inducing system according to any of the variousembodiments described herein may be incorporated into any of a widevariety of peripheral control devices, such as the illustrated computermouse 1153. The finger 1110 used to control the mouse 1153 may have afinger pad 1115 on a control surface 1152. A system configured to inducecutaneous sensations using transcutaneously focused electromagneticradiation may be integrated with the control surface 1152. A pressuresensitive feedback mechanism may be used to modulate the impartedstimulation in proportion to the pressure exerted by the user. Inanother embodiment, the finger pad 1115 may be held away from anyphysical surface similar to the concept described in conjunction withFIG. 5B.

FIGS. 12A-C illustrates three embodiments for incorporating a system forinducing cutaneous sensations via transcutaneously focusedelectromagnetic radiation within a surface 1220. As illustrated in FIG.12A an electromagnetic radiation source 1250 may be positioned beneath asurface 1220, such as a touch pad, track pad, or display. For example,the surface 1220 may be part of an off-display embodiment where there isno visual information conveyed, or it could be a visible display that isinteractive both for vision and touch. In an embodiment in which thesurface 1220 is a display, the display could be any number of differentdisplay types including, but not limited to, LCD, LED, OLED, AMOLED,e-ink, array of controllable mirrors, or digital micromirror device. Thedisplay may be substantially transparent to the electromagneticradiation used for stimulation.

Alternatively, the electromagnetic radiation from the source 1250 may betransmitted via channels or vias in the surface 1220. FIG. 12Aillustrates an embodiment in which a source 1250 is directly beneath thesurface 1220. FIG. 12B illustrates an embodiment in whichelectromagnetic radiation from the source 1250 is directed by an opticalscanner 1255 through the surface 1220 and onto/into a finger 1210. FIG.12C illustrates an embodiment in which electromagnetic radiation from asource 1250 is directed through an optical scanner 1255 to a series ofreflective mirrors 1260 with angled surfaces 1265 in order to reflectthe electromagnetic radiation onto/into the finger 1210 of a user. Theoptical scanner 1255 may be configured to irradiate multiple points onthe finger to induce cutaneous sensations.

FIG. 13 illustrates an example of a display 1300 with an integratedsystem 1320 for inducing cutaneous sensations via transcutaneouslyfocused electromagnetic radiation. As illustrated, a display surface1310 may include a series of LEDs or other visible light sources 1327clustered on the display as pixels 1325. Electromagnetic radiationsources for inducing cutaneous sensations via transcutaneously focusedelectromagnetic radiation may be integrated within the display surface.In some embodiments, the electromagnetic radiation sources may be formedon the same substrate. The electromagnetic radiation sources may includeLEDs, laser diodes, IR light sources, VSCELs, and/or other suitablesources. The proximity of the sensation inducing sources to the fingerof a user may reduce the power requirements required to inducesensations. A digitizer or other technology may be used to sense thelocation and area of contact of a user's finger (or fingers, hand,portion of the body, etc.). Limiting stimulating emissions to thoseareas where the target tissue is touching the screen may minimize energywaste.

It may be desirable to minimize or eliminate sensation-inducingelectromagnetic radiation in any location except for a desired locationand area of contact (i.e., where a finger is). Certain wavelengths ofelectromagnetic radiation may cause damage to the eye at highintensities, such as the corneal surface, lens, or retina. FIG. 14Aillustrates a schematic of a relatively thin fluid layer 1445 on asurface 1440 configured to prevent stray electromagnetic radiationemissions. The fluid layer 1445 may absorb, reflect, or refractsensation-inducing electromagnetic radiation and prevent it fromnegatively impacting a user. FIG. 14B illustrates a finger 1410depressing the relatively thin fluid layer 1445 with a finger pad 1415.The depression 1450 may vacate a sufficient amount of the fluid to allowthe sensation-inducing electromagnetic radiation to penetrate the fingerpad 1415. The fluid layer 1445 may allow visible light to pass withminimal attenuation and optical distortion.

FIGS. 15A-15C illustrate an embodiment of a display 1510 with anintegrated system for inducing cutaneous sensations via transcutaneouslyfocused electromagnetic radiation, utilizing an array of lenslets andVCSELs 1513. As illustrated in FIG. 15A, a touch screen display 1510 mayinclude one or more functional layers 1511, 1512, and 1513 manufacturedas a single physical layer or as discrete physical layers. A touchsensitive layer 1511 may be configured to receive touch inputs from afinger or fingers of a user. A transmissive or reflective Spatial LightModulator (SLM) Layer 1512 may be configured to modulate visible lightand/or other electromagnetic radiation. A third layer 1513 may includean N×N array of lenslets with integrated VCSELs. Each lenslet may be adiscrete lens aligned with a VCSEL in order to collimate the upwardemitting VCSEL output.

As illustrated in FIG. 15B, the collimated electromagnetic radiation maythen traverse the transmissive spatial light modulator layer 1512 wherethe wave front 1550 could be arbitrarily modulated prior to beingtransmitted through the touch sensitive layer 1511. The electromagneticradiation from the VCSELs may be used to induce cutaneous sensations bytranscutaneously focusing the electromagnetic radiation on a user'sfinger(s) 1510. In various embodiments, the electromagnetic radiationmay be transmitted through the display/touch screen layer(s) 1511. Forinstance, if the wavelength of the sensation-inducing electromagneticradiation is about 1300 nm, the electromagnetic radiation may betransmitted with minimal loss through silicon. Furthermore, in variousembodiments, the location of the finger 1510 on the touch screen 1511may be detected by the touch screen and used by the controller of thesystem for inducing cutaneous sensations via transcutaneously focusedelectromagnetic radiation.

In various embodiments, the SLM layer 1512 may be used to optimizefocusing on the surface or inside human tissue through close-loopfeedback control. For example, the wave front of the electromagneticradiation may be modulated in a systematic fashion. After eachalteration of the wave front, a user may provide feedback based on thestrength of the tactile sensation. Convergence to an optimum wave frontmay be achievable after a number of iterations during an initialcalibration phase. An adaptive focusing scheme may be used to increasefocal intensity by several folds. The focused/modulated electromagneticradiation may be scanned over the finger by imposing a dynamicallychanging phase grating pattern using the SLM layer 1512. SLM basedoptical scanning has the advantage of size and speed, eliminating theneed for mechanical scanner and the inertia associated with it.

Additionally, as illustrated in FIG. 15C, the SLM layer 1512, may imposea grating or dot pattern 1555 for scanning stimulation spots andrasterization schemas. The grating 1555 may be formed as a distinctlayer in addition to the SLM layer 1512, or in place of the SLM layer1512. Additionally, it may be possible to create a variety of staticpatterns using diffractive optical elements and/or selectivelyactivating pixels of the SLM.

The above description provides numerous specific details for a thoroughunderstanding of the embodiments described herein. However, those ofskill in the art will recognize that one or more of the specific detailsmay be omitted, modified, and/or replaced by a similar process orsystem.

What is claimed is:
 1. A system configured to induce a cutaneoussensation in a user of an electronic device based upon a tactileapplication executable on the electronic device, the system comprising:a stimulation system configured to generate an output operable to exciteneural tissue; an interface component configured to direct the output ofthe stimulation system onto a target area of skin of the user; and acontroller configured to generate a control signal to cause thestimulation system to modify one or more characteristics of the outputof the stimulation system in order to induce a cutaneous sensation basedupon a tactile application executable on the electronic device.
 2. Thesystem of claim 1, wherein the interface component is further configuredto direct the output of the stimulation system onto the target areawhile the target area is in physical contact with the interfacecomponent.
 3. The system of claim 1, wherein the interface component isfurther configured to direct the output of the stimulation system ontothe target area while the target area is physically separated from theinterface component.
 4. The system of claim 1, wherein the electronicdevice comprises a computer and the interface component comprises amouse.
 5. The system of claim 4, wherein the mouse comprises a controlsurface, and the target area comprises a finger pad of a user thatinteracts with the control surface.
 6. The system of claim 4, whereinthe control surface comprises one of a button, a touch pad, and a trackpad.
 7. The system of claim 1, wherein the electronic device comprises acomputer and the interface component comprises a keyboard.
 8. The systemof claim 1, further comprising a display component, the interfacecomponent being distinct from the display component, and wherein thecontroller is configured to modify one or more characteristics of theoutput of the stimulation system based on an object on the displaycomponent.
 9. The system of claim 8, wherein the sensation correspondsto an object appearing on the display component.
 10. The system of claim1, wherein the electronic device comprises one of a telepresencemedicine device, a gaming device, a tablet computer device, a telephonedevice, an electronic Braille display device, an industrial controlstation, entertainment system, and an electronic surgical controldevice.
 11. The system of claim 1, wherein the system further comprises:a thermal feedback system configured to measure a temperature associatedwith the target area; and wherein the controller is configured todynamically control the stimulation system to maintain the temperaturebelow a threshold temperature.
 12. The system of claim 1, wherein theoutput of the stimulation system comprises one of infraredelectromagnetic radiation and visible electromagnetic radiation
 13. Thesystem of claim 1, wherein the stimulation system comprises a laseremission system.
 14. A method for inducing a cutaneous sensation in auser of an electronic device, the method comprising: executing a tactileapplication on an electronic device; generating, using an stimulationsystem associated with the electronic device, an output operable toexcite neural tissue; directing the output of the stimulation systemonto a target area of skin of a user using an interface component; andgenerating a control signal to cause the stimulation system to modifyone or more characteristics of the output of the stimulation system inorder to induce a cutaneous sensation based upon the tactile applicationexecuting on the electronic device.
 15. The method of claim 14, whereindirecting the output of the stimulation system onto the target areaoccurs while the target area is in physical contact with the interfacecomponent.
 16. The method of claim 14, wherein directing the output ofthe stimulation system onto the target area occurs while the target areais physically separated from the interface component.
 17. The method ofclaim 14, further comprising: displaying an object on a displaycomponent; and wherein the sensation corresponds to the object displayedon the display component.
 18. The method of claim 14, wherein theelectronic device comprises one of a telepresence medicine device, agaming device, a tablet computer device, a telephone device, anelectronic Braille display device, an industrial control station, and anelectronic surgical control device.
 19. The method of claim 14, furthercomprising: measuring a temperature associated with the target area; andwherein the controller is configured to dynamically control thestimulation system to maintain the temperature below a thresholdtemperature.
 20. The system of claim 1, wherein the output of thestimulation system comprises one of infrared electromagnetic radiationand visible electromagnetic radiation.